{
  "bibcode": "2014GCN.16806....1G",
  "body": "E. Gorbovskoy, V. Lipunov, M.Pruzhinskaya, V.Kornilov, D.Kuvshinov, \nN.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, \nD.Denisenko,  A.Sankovich\nLomonosov Moscow State University,\nSternberg Astronomical Institute, Moscow State University\n\nV.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A. Gabovich\nBlagoveschensk Educational State University, Blagoveschensk\n\nK.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk\nIrkutsk State University\n\nV.Krushinski, I.Zalozhnih,  A. Popov\nUral Federal University, Kourovka\n\nA. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik\nKislovodsk Solar Station of the Pulkovo Observatory\n\nHugo Levato and Carlos Saffe\nInstituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)\n\nClaudio Mallamaci, Carlos Lopez and Federico Podest\nObservatorio Astronomico Felix Aguilar (OAFA)\n\nMASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) \nlocated in Blagoveschensk was pointed to the  GRB140907A 6987 sec after \nnotice time and 7504 sec after trigger time at 2014-09-07 18:12:13 UT \ndirectly after weather conditions became suitable. On our first (180s \nexposure)  set we found optical transient  within Swift error-box (ra=03 \n12 34 dec=+46 36 18 r=0.050000) on coadditional images in two epoch.\nThe protometry results available at Table 1.\n\n\nTable 1.\n\nDate and  Time start  T_trig-Tmid  Exptime    Mag   err.mag\n\n2014-09-07 18:12:13.4   7809        540      19.0     0.2\n2014-09-07 19:23:43.6  12547       1260      19.4     0.2\n\nThe  approximate power law index (alpha) from 7000 to 13000 seconds after \nthe trigger is  about 0.81 +- 0.1  (F ~ t^-alpha).\n\nAnother two MASTER-II robotic telescop located in Kislovodsk and Tunka \nmade upper limit observations only in earlier time due to weather \nconditions and high zenith distance of object.  MASTER II  in Tunka was \npointed to the  GRB140907A  1021 sec after trigger time at 2014-09-07 \n16:24:10 directly after weather conditions became suitable. On our first \n(180s exposure) image we haven`t found optical transient up to 16m. MASTER \nII in Kislovodsk starting observations  GRB140907A 17 sec after notice \ntime and 77 sec after trigger time at 2014-09-07 16:08:25 using FERMI GBM \ncoordinates. However OT position was not covered by MASTER-II. The \ntelescope pointing by Swift trigger 22 sec after notice time and 540 after \ntrigger time at 2014-09-07 16:16:08.  On first (110s exposure) image we \nhaven`t found optical transient up to 12.5 m. The zenith distance of \nobject z~85 d.\n\nOur white (clear) band is well described by a parity 0.8R+0.2B (USNO B1).",
  "circularId": 16806,
  "createdOn": 1410267833000,
  "email": "gcncirc@observ.inetcomm.ru",
  "subject": "GRB 140907A: MASTER optical observations",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>",
  "eventId": "GRB 140907A"
}